Sen. John McCain declares in an exclusive interview with Newsmax TV that the United States must now take military action in Syria — establishing a “safe zone’ for the rebels battling President Bashar al-Assad — without putting any American “boots on the ground.”

“They should make sure that they’re not attacked from the air — and provide them with the weapons of training that they need, and the ability of their revolutionary council to organize and to govern — the same way that the Libyan consulate did in Benghazi,” McCain, the 2008 GOP presidential candidate, tells Newsmax. “That way, they can prevent these weapons from falling into the wrong hands.”

“Under no circumstances should we put boots on the ground,” McCain adds. “What we could do is use the Patriot missiles to protect the area. We could also use Cruise missiles and destroy Bashar Assad’s air on the ground — and we would not have to take out their air defenses around Damascus.

“We could just establish a zone along the border where they can organize, operate, govern, and train and equip and that would be enough to tip the scales.”

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The Arizona senator’s comments to Newsmax come as Defense Secretary Chuck Hagel said on Thursday that Assad’s regime likely had used the chemical weapon sarin against its people.

Hagel’s announcement — based on “varying degrees of confidence” — represented a reversal for the White House.

President Barack Obama has said that the use of chemical weapons by Syria, or the transfer of stockpiles to terrorist groups, would be a "red line" that could trigger U.S. reaction.

“It has,” McCain tells Newsmax on whether the “red line” had been crossed by Assad — and it follows confirmation by British, French, and Israeli intelligence sources.

“This is an extremely concerning use of chemical weapons as a war crime,” he says.

But despite the confirmations, McCain adds, “the White House seems to be not committed. In other words, the president may not take the action that is absolutely necessary to stop the stalemate and the carnage.

“They have turned a blind eye to the torture, rape, murder of thousands and more than 70,000 Syrian refugees — and I can tell you that the Syrians are angry and bitter that we did not intervene to assist them.

“Our intelligence people are telling us that now, under the status quo, it’s at least three to six more months of stalemate and massacre,” says McCain, a ranking member of the Senate Armed Services Committee.

The civil war in Syria has lasted for more than two years. The United Nations estimated in February that more than 70,000 people had died since the conflict began.

The safe zone is the only way to purge al-Assad, McCain says.

“The only thing that will lead to the removal of Bashar al-Assad is the certainty that he will lose — and the way he can be convinced that he’s going to lose is if we have a safe zone, the training and equipment of the rebels, and the certainty that they will, over time, have the capability to overthrow him.”

Long term, it also is in America’s national security interest that Assad be removed. McCain cites an observation by Marine Corps Gen. James Mattis, the outgoing commander of U.S. troops in the Middle East and South Asia.

“The fall of Assad would lead to the greatest blow to Iran in 25 years. Every day that goes by, more and more jihadists flow in, the more complicated the post-Assad era will be — and all of these problems were not there two years ago, when we should have acted to help these people.

“This is one of the most shameful chapters in American history.”

Turning his attention to last week’s bombings at the Boston Marathon that killed three and injured 264 others — and its two suspects — McCain tells Newsmax that “there are too many questions that need to be answered.”

The senior senator, specifically, cites information regarding Tamerlan Tsarnaev, the 26-year-old who died in a fierce gun battle with police on Friday just outside Boston.

His brother, Dzhokhar, 19, was arrested Friday night after an intense manhunt and now is listed in fair condition at a Boston hospital. He remains under heavy police guard.

Russian authorities approached both the CIA and the FBI about the elder brother’s possible ties to radical Islamic groups in his native Chechnya.

Both agencies placed him on watch lists managed by the Department of Homeland Security — and those databases “pinged” twice last year when Tamerlan went on a six-month trip to Russia, investigators have said.

Homeland Security did not share that information with the investigative agencies. Questions about whether the governmental agencies are cooperating continue to surface in the investigation.

“We need to know what the older brother did during his absence in Russia, but this may be a new kind of al-Qaida, the kind that is influenced by the Internet and jihadist messages that cause them to become more and more radicalized and consider themselves part of al-Qaida, but we ought to reserve judgment until we get all the facts,” McCain tells Newsmax.

But, more broadly, “Why was it that when he left to go to Russia only the Department of Homeland Security knew?” he asks. “No one was notified. There’s no doubt that his activities on the Internet and statements showed more and more radicalization.

“It seems that the two warnings from the Russians — one to the FBI and another to the CIA later on — probably should have been paid a lot more attention to,” McCain adds, calling for a hearing before the Senate Homeland Security and Governmental Affairs Committee — a panel on which he also sits.